An air seed meter includes a reservoir for receiving and storing seed for planting, and a vacuum chamber which is typically evacuated by a powered fan, creating a partial vacuum (i.e. a sub-atmospheric pressure) on a disc having seed apertures and mounted for rotation between the seed reservoir and the vacuum chamber. Thus, seeds are secured to the rotating disc by differential air pressure, and released as a seed opening securing the seed passes out of the vacuum chamber and is exposed to the atmosphere.
There are many different types of debris smaller than seeds which may interfere with the efficient and accurate operation of this type of meter. These particles may include burrs from cotton plants, fragments of seed chipped off from handling and not separated from the seed, fragments created in the meter itself, or other remnants or plugs capable of being lodged in a seed opening secured by the pressure differential, and either affecting (i.e. diminishing) the desired retaining value of the vacuum, or preventing the seed from being lodged in a seed opening. Moreover, foreign material may also be found mixed in the seed as the farmer purchases it. Thus, there are many types of undesired foreign material other than seed remnants and chips which may interfere with the accurate, efficient operation of an air seed meter, primarily because this type of meter relies on a source for suctioning air or compressing air to secure the seeds to a rotating seed disc for the purpose of spacing, singulation and delivery of the seed and the pressure differential across a seed opening has a tendency to gather debris and convey it through a seed opening, but the debris may get caught in the seed opening.
It is thus desirable to clear debris (which is broadly intended to include all undesired seed remnants, foreign material, “burrs” or other particulate matter other than seed which may tend to plug or accumulate in the seed openings).
Different types of solutions to this debris problem have been proposed, such as the use of compressed air to clean the seed disc openings. Some prior attempts to solve this problem have required the use of supplementary power, such as the compressed air mentioned, or that the clearance devices be permanently attached to the meter.